Heretofore, a variety of artificial substrates or artificial reefs have been proposed, constructed, and placed on a water bottom for the building of marine habitats.
Most of these artificially built marine habitats are of low relief, often less than one meter above the water bottom. An example of these low relief habitats is the "Self anchoring tire-made artificial reef" of my invention that I proposed in application Ser. No. 115,455 of Sep. 1, 1993.
Seldom artificial habitats rising tens of meters and more above the floor of a body of water have been proposed. Some devices are known which float in superficial waters as, for example, the fish attraction device F.A.D. These attraction devices are not to be confused with the present invention because they are exclusively made for attracting and catching fish but not to feed and shelter fish.
On Apr. 7, 1987, in my application Ser. No. 35,449, and on Aug. 10, 1989, in my application Ser. No. 392,055, I proposed the use of buoyant tubes, floating several meters high in the water column. These tubes are made for shallow waters. They affix vegetal and animal organisms and they offer to fish large quantities of food as well as relative shelter. But, these buoyant tubes are too fragile to be used on a very extended height. One weakness is in the mooring's single point where resistance to traction equals the resistance of the plastic material the tubes are made of. For extended height, a special reinforcement of the plastic tubes, at their mooring point and all along their length, would be unavoidable and costly. Moreover, joining one tube to another tube and repeating the operation on a great length would also be fragile and costly. Another difficulty with long buoyant tubes is that they are difficult to move in and out the water for maintenance and/or aquacultural work. Also, these tubes which stand vertically underwater, as trees in a forest, do not offer a sufficient shield for small fish against predators and strong water movement. For juvenile fish a special protection is needed. Repopulating depleted fisheries by protecting juvenile fish is the most important function of marine habitats